Streets as areas at high zooms

[kocio-pl]

I guess it's time to start thinking about rendering highways as areas at higher zoom levels. Pedestrian/footway areas are already possible (and used), so I think about the streets. I'm not sure what model would we use, but I think this draft is quite interesting:

http://wiki.openstreetmap.org/wiki/Street_area

I also don't know what is technically possible to render right now and what needs to be prepared yet, but I think we could start at the highest available zoom with at least rendering the street outlines.

[matthijsmelissen]

As area:highway is not in the database, this would require a database reload.

[kocio-pl]

Then it probably depends on #1286 - but even if it takes some months before next db reload, I'd like to know if it will be included there at all.

BTW - demo of this feature is made as a script for Maperitive:
https://github.com/javnik36/highway-area-style

I have also the idea to drop colouring by street type then (on highest zoom only) and start rendering them by surface type - I think that plus the real width and geometry would be more useful in micro scale.

[pnorman]

dupe of #180